Considerable confusion surrounds the attention concept; this is particularly unfortunate given its importance to human information processing. This paper attempts to show, first that attention is less confusing when conceptualized, not as a single process, but as several distinct processes, each of which contributes in a different way to the selection capability of the organism. Second, it suggests a developmental and an evolutionary sequence for the appearance of these different processes. Note the way in which each successive process provides an increment in adaptive flexibility.
This article will present a good challenge to your active reading skills.
Many theories have been proposed as to why the brain is lateralized into two similar, yet not identical, hemispheres. A common theory seems to be the idea that each human can choose either a right-brained or a left-brained approach to a problem and that each individual has a preferred approach.
Kinsbourne offers an alternative theory, supported by some data, which he calls the functional cereberal distance principle. Central to this theory is the idea that brain activities in close cerebral proximity easily interfere with each other (due, perhaps, to an inhibitory fringe). Thus activities that would be useful to have running simultaneously might best occur in cerebrally distant areas of the brain. Further, the very organization of the brain, he claims, encourages this separation.